• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1992년도 봄 학술발표회 논문집
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• pp.105-110
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• 1992

This study deals with the effect of a series of moving trucks on the Dynamic Load Factor (DLF). The DLF is calculated by investigating the load effect of moving trucks. Therefore, analytical models for frocks, bridge, and road profiles were developed and dynamic structural analysis computer program were developed. Then the DLFs are calculated as a ratio of maximum dynamic load effect and maximum static load effect. Trucks used in this study are 5 axle semi tractor-trailer with the weight of 36 and 54 ton. Simply supported prestressed concrete box girder bridges with 20 and 40m span length are selected. From the results of the DLF for various headway distances, they show a very scattered and relatively high values of the DLF in case of a 20m span length bridge. For a 40m span length bridge, the results show less scattered and small increase of the DLF compared to a 20m span length bridge.

• Journal of Ginseng Research
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• 제22권3호
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• pp.200-205
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• 1998

Isolated rabbit jejunal segments were used to study the effects of ginseng total saponins (GTS) , protopanaxatriol saponins (PT) and protopanaxadiol saponins (PD) on intestinal contractility. GTS, PT and PD caused a dose-dependent decrease in intestinal spontaneous movements, and PT was the most efficacious of them. The effect of GTS, PT and PD were not blocked by pretreatment with phentolamine (10-6 M), yohimbine (10-6 M), d1-propranolol (10-6 M), naloxone(10-6∼10-5M), Nu-nitro-L-arginine methyl ester (10-4 M), methylene blue (10-5M), and N-ethylmaleimide (10-4 M). However, pretreatment with tetraethylammonium chloride (3-10 mM) antagonized the effect of GTS, PT and PD. Furthermore, 4-amlnopyridine (1 mM) also inhibited the effect of GTS, PT and PD. The results suggest that GTS, PT and PD inhibited the spontaneous movements in isolated rebait jejunum by causing hyperpolarization through an activation of K+ channels directly.

• Archives of Pharmacal Research
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• 제29권1호
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• pp.34-39
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• 2006

The antispasmodic and vasodilator activities of a newly synthesized piperidine derivative (1-(4'fluorophenacyl)-4-hydroxy-4-phenyl-piperidinium chloride) were studied in vitro. The test compound exhibited a dose-dependent relaxant effect on the spontaneous and $K^+$ (75 mM)-induced contractions of isolated rabbit jejunum with respective $EC_{50}$ values of 0.01 mM(0.01-0.02, 95% CI) and 0.30 mM (0.17-0.56). The $Ca^{++}$ channel blocking (CCB) activity was confirmed when the test compound (0.1-0.2 mM) shifted the $Ca^{++}$ dose-response curves to the right, similar to that produced by verapamil ($0.1-1.0{\mu}M$), a standard CCB. In the isolated rabbit aorta, the test compound showed a dose-dependent vasodilator effect on $K^+$ (75 mM)-induced contractions with an $EC_{50}$ value of 0.08 mM (0.02-0.26) while also suppressed the norepinephrine ($1{\mu}M$) control peak responses with $EC_{50}$ value of 0.08 mM (0.05-0.13, n=5). When tested in Langendorff perfused rabbit heart preparation, the test compound exhibited a negligible inhibitory effect on the rate or force of atrial and ventricular contractions when tested up to 5 mM. The results show smooth muscle-selective relaxant effect of the test compound on intestinal and vascular preparations mediated possibly via blockade of voltage and receptor-operated $Ca^{++}$ channels.

• 로봇학회논문지
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• 제15권3호
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• pp.248-255
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• 2020

This paper introduces a Feedback Linearization (FL) controller to eliminate the gyro effect on a quadrotor UAV. In order to control the attitude of the quadrotor, the second model equation was differentiated to the 4-th order to induce the control input to be revealed, and then a new control input was derived based on the attitude transformation equation with a gyro effect. For the initial quick posture control of the quadrotor, the existing yaw control was replaced with a separate controller. The simulation was conducted with an experiment in which FL control to remove the gyro effect was applied to the quadrotor and an experiment without removing the gyro effect, from the experimental results, the maximum error seen in each axial direction of the quadrotor was x = 0.22 m, y = 0.20 m, z = 0.16 m. Through the proposed method, the effect of the FL controller for controlling the gyro effect of the quadrotor was confirmed.

• The Korean Journal of Physiology and Pharmacology
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• 제1권6호
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• pp.783-796
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• 1997

The relaxation induced by stimulation of the inhibitory non-adrenergic, non-cholinergic (iNANC) nerve is mediated by the release of iNANC neurotransmitters such as nitric oxide (NO), vasoactive intestinal peptide (VIP) and adenosine triphosphate (ATP). The mechanisms of NO, VIP or ATP-induced relaxation have been partly determined in previous studies, but the detailed mechanism remains unknown. We tried to identify the nature of iNANC neurotransmitters in the smooth muscle of guinea pig ileum and to determine the mechanism of the inhibitory effect of nitric oxide. We measured the effect of NO-donors VIP and ATP on the intracellular $Ca^{2+}$ concentration$([Ca^{2+}]_i)$, by means of a fluorescence dye(fura 2) and tension simultaneously in the isolated guinea pig ileal smooth muscle. Following are the results obtained. 1. Sodium nitroprusside $(SNP:10^{-5}\;M)$ or S -nitro-N-acetyl-penicillamine $(SNP:10^{-5}\;M)$ decreased resting $[Ca^{2+}]_i$ I and tension of muscle. SNP or SNAP also inhibited rhythmic oscillation of $[Ca^{2+}]_i$ and tension. In 40mM $K^+$ solution or carbachol ($(CCh:10^{-6}\;M)$-induced precontracted muscle, SNP decreased muscle tension. VIP did not change $[Ca^{2+}]_i$ and tension in the resting or precontracted muscle, but ATP increased resting $[Ca^{2+}]_i$ and tension in the resting muscle. 2. 1H-[1,2,4]oxadiazol(4,3-a)quinoxalin-1-one $(ODQ:1\;{\mu}M)$, a specific inhibitor of soluble guanylate cyclase, limited the inhibitory effect of SNP 3. Glibenclamide $(10\;{\mu}M)$, a blocker of $K_{ATP}$ channel, and 4-aminopyridine (4-AP:5 mM), a blocker of delayed rectifier K channel, apamin $(0.1\;{\mu}M)$, a blocker of small conductance $K_{Ca}$ channel had no effect on the inhibitory effect of SNP. Iberiotoxin $(0.1\;{\mu}M)$, a blocker of large conductance $K_{Ca}$ channel, significantly increased the resting $[Ca^{2+}]_i$, and tension, and limited the inhibitory effect of SNP. 4. Nifedipine $(1\;{\mu}M)$ or elimination of external $Ca^{2+}$ decreased not only resting $[Ca^{2+}]_i$ and tension but also oscillation of $[Ca^{2+}]_i$ and tension. Ryanodine $(5\;{\mu}M)$ and cyclopiazonic acid $(10\;{\mu}M)$ decreased oscillation of $[Ca^{2+}]_i$ and tension. 5. SNP decreased $Ca^{2+}$ sensitivity of contractile protein. In conclusion, these results suggest that 1) NO is an inhibitory neurotransmitter in the guinea pig ileum, 2) the inhibitory effect of SNP on the $[Ca^{2+}]_i$ and tension of the muscle is due to a decrease in $[Ca^{2+}]_i$ by activation of the large conductance $K_{Ca}$ channel and a decrease in the sensitivity of contractile elements to $Ca^{2+}$ through activation of G-kinase.

• 한국식품영양과학회지
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• 제30권1호
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• pp.143-151
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• 2001

A marine bacterium producing carotenoid was isolated from the Yosu coastal area of South Korea, which was recorded as MCK-1. It was identified as Erythrobacter sp. Optimium conditions of marine carotenoid fermentation from Erythrobacter sp. were pH 6.0, a temperature of $25^{\circ}C$, 16 mM mannitol as a carbon source, 0.5% tryptone as a nitrogen source, 0.1 mM $Fe^{+2}$ ion as a mineral source and 1$\mu$M of cyanocobalamine as a growth factor in a jar-fermentor. Erythrobacter sp. was produced 351.27 mg/100mL of the marine carotenoid in these optimum conditions. This marine carotenoid was composed of 4 different conpounds, like as notoxanthin (61.4%), can thaxanthin (24.6%), fucoxanthin (8.2%), and zeaxanthin (5.8%). Physiological properties including antibacterial activity, cytotoxic effect, antioxidative effect and free radical scavenging activity were characterized with crude carotenoid. Carotenoid exhibited no antibacterial activity against E. coli and lactobacillus bulgaricus, but showed cytotoxic effect against cancer cells such as HepG2 (Hepatocellular carcinoma, human, ATCC HB-8065) and HeLa (Cervical carcinoma, human, ATCC CCL-2) cells. The impediment ratios for HepG2 and HeLa cell were 37.14% and 33.78%, respectively. This carotenoid expressed a strong antioxidative effect (77%) against CCL-13 5 $\mu\textrm{g}$/mL and 50 $\mu\textrm{g}$/mL crude carotenoid, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제31권10호
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• pp.1542-1549
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• 2018

Objective: Because lactation periods in dairy cows lengthen with increasing total milk production, it is important to predict individual productivities after 305 days in milk (DIM) to determine the optimal lactation period. We therefore examined whether the random regression (RR) coefficient from 306 to 450 DIM (M2) can be predicted from those during the first 305 DIM (M1) by using a RR model. Methods: We analyzed test-day milk records from 85,690 Holstein cows in their first lactations and 131,727 cows in their later (second to fifth) lactations. Data in M1 and M2 were analyzed separately by using different single-trait RR animal models. We then performed a multiple regression analysis of the RR coefficients of M2 on those of M1 during the first and later lactations. Results: The first-order Legendre polynomials were practical covariates of RR for the milk yields of M2. All RR coefficients for the additive genetic (AG) effect and the intercept for the permanent environmental (PE) effect of M2 had moderate to strong correlations with the intercept for the AG effect of M1. The coefficients of determination for multiple regression of the combined intercepts for the AG and PE effects of M2 on the coefficients for the AG effect of M1 were moderate to high. The daily milk yields of M2 predicted by using the RR coefficients for the AG effect of M1 were highly correlated with those obtained by using the coefficients of M2. Conclusion: Milk production after 305 DIM can be predicted by using the RR coefficient estimates of the AG effect during the first 305 DIM.

• Geomechanics and Engineering
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• 제31권4호
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• pp.385-393
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• 2022

Previous studies postulated insignificant capillary rise (h_c) effect above the water table (H_w) for unsaturated soils. In addition, these studies utilised dry unit weight above H_w. This paper, therefore, addresses the effect of these postulations on strength where the influence of h_c using a modified upper bound approach, Discontinuity Layout Optimization (UNSAT-DLO) for a simulated soil was predicted. Two different parametric studies to model passive earth pressure and bearing capacity problems are carried out to provide an insight into the effect of capillary rise on strength. Significant increase in strength, owing to unsaturated conditions, was obtained where the maximum increase was when suction slightly less or greater than the air entry suction. On the other hand, the results showed a negative effect of h_c. For example, up to 8.24% decrease in passive thrust (P_p) was obtained at H_w=0 m when h_c rose 1 m from 0 m. To put this into perspective, this was equivalent to a decrease of about 2° in 𝜙 at H_w=0 m and h_c =0 m in order to obtain the same result at h_c =1 m. For the bearing capacity problem, the effect was seen to be higher, up to 18.4% decrease in N_𝛾 was obtained when h_c rose from 0 m to 2.5 m at H_w =0 m. In addition, the results revealed a negative influence of assigning dry unit weight above H_w or h_c.. However, considerable increase in strength was obtained when unsaturated unit weight above h_c was assigned.

• 설비공학논문집
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• 제12권3호
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• pp.267-276
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• 2000

A numerical study has been carried out to find out the optimal design condition of a solar absorption cooling system. The system was composed of solar collectors and an absorption chiller with LiBr/water The System performance with commercial single effect(SE) cycle and a new single effect/double lift(SE/DL) cycle utilizing low temperature hot water was calculated and compared. It was found that the required solar collector area grew exponentially as the overall heat loss coefficient of solar collectors increased. For instance, the required area for cooling capacity of 1 USRT was $17m^2$ if heat loss coefficient was 4 W/$m^2\;cdot\;K$. If heat loss coefficient was doubled($8\;W/m^2\;cdot\;$K), the required collector area was increased by 6 times($100m^2$) .It was also found that the SE-cycle as the heat loss coefficient of solar collectors increased. Generally, a SE/DL-cycle seems to be more advantageous than a SE-cycle if loss coefficient of solar collector is greater than 4 W/$m^2\;cdot\;K$.

• 한국응용곤충학회지
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• 제4권
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• pp.11-18
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• 1965

Phenylmercuric 8-Oxyquinolinate의 광범위한 식물병원균에 대한 살균작용, 식물의 수분증산억제작용, 식물에 대한 약해작용, Gas작용 및 자외선에 의한 경시변화에 관해 실험을 행하였으며, 그 결과를 요약하면 다음과 같다. (1) 포자발아억제작용은 P.M.A.보다 약간 불량한 결과를 보이며, 균사생장억제작용은 P.M.A. 보다도 양호하였다. (2) 식물의 수분증산억제작용은 초기에는 8-Hydroxyquinoline sulfate가 P.M.Q.보다도 강한 억제작용을 나타내었으나, 끝에 가서는 반대로 P.M.Q가 Oxine sulfate보다도 강한 작용을 나타냈다. (3) 수도종자의 발아, 발근에 미치는 영향은 P.M.A. 보다 약해가 적었고 수도 및 대두의 유식물의 경엽(40ppm 처리)에도 약해가 없었다. (4) 식불병원균에 대한 Gas효과에 의한 살균력은 P.M.A.보다 적었다. (5) 자외선에 의한 영향은 생물학적인 변화와 화학적인 변화가 거의 일치하였으며 P.M.Q.는 P.M.A.보다도 훨씬 자외선에 안정하였다. 이상의 결과로 보아 본약제는 광범위한 식물병원균에 대해 살균작용을 가지고 있고 식물의 수분증산도 억제시키며 이화학적인 안정성을 가진 유망한 살균제가 될 것으로 생각된다.